Clamping mechanism



May 1 1923. v 1,453,350

H ;w. HACKER CLAM'PING MECHANISM Filed ,June 13 1921 2 Sheets-Sheet l 1450mm w May 1, 1923.

H. w. HACKER HUWM MA A:

l atented lt llay" ll,

HORACE "W. HACKER, O15 CHICAGi-U, TLLIll'UiEh-l.

CLAIVHPTNG lVlElEClEEANISJlE.

application filed June 13, 1921.

To all whom it may concern:

die it known that l, Hermon W. lineman, citizen of the United States, residing at Chicago, in the county of ()ookand State of Illinois, have invented a certain new and useful Improvement in Clamping Mecha nism, of which the following is a full, clear, concise, and exact description.

My invention relates to clamping mechanism having a bed for levelling or defining the uprightposition of the object clamped and clamping jaws assembled with the bed, and resides in providing devices for pressing the jaws toward the bed whereby the object held therebetween is pressed upon the bed tohave its upright position thereby defined.

in. the preferred embodiment of the invention the bed is. formed with an elongated slot and there a shaft journaled upon the bed and beneath the slot along which the shaft extends. There are also two blocks in threaded connection with the shaft, the threads in one bloclrandthe portion of the shaft engaging this block being opposite in direction to the threads in the other block and the portion of the shaft engaging this latter block, said blocks crossing and extending beyond said. slot and underlying the bed. The clamping jaws are movable by said blocks along the slot and up and down with reference thereto independently thereof. Screw devices are provided upon the blocks and are in depressing engagement with the j aws tofirmly locate the object held between the jaws upon the blocks. Springs arealso desirably provided between the jaws and the bed for elevating the jaws when the screw devices are not adjusted to depress the jaws whereby said jaws are normally positioned slightly above the bed to afford a range of depression therefor to enable the object that is heldubetween the jaws to: be firmly pressed upon the bed when the screw devices are tightened.

The clamping mechanism of my invention is of particular service when employed in conjunction with a planer as by means of the clamping device. The height of the object to. be planed. is determined solely by the distance between the cutting edge of the planing tool and the surface ofthe bed: upon whichthe object that is to be planed rests.

T have embodied the clamping mechanism of my invention in what if term to be a type high planer, the printing block or other printing element being interposed between the jaws and held upon the bed, the space between the bed and the planing tool being type-high.

The invention in all of its aspects in fully illustrated by the accompanying drawings in which Fig. 1 is a plan view of the mechanism of my invention, parts being shown by dotted lines and the printing block that is clamped between the jaws being broken away to reveal mechanism that is beneath it; Fig. 2 is a sectional View on line 2-2 of Fig. 1; Fig. 3 is a sectional view on line 3-'3 of Fig. 1; and Fig. i is a sectional view on line dl of 1 but with the illustrated jaws clamped against the bed.

Trike parts are indicated by similar characters of reference tl'irougbout the different figures.

The clamping device illustrated includes a bed 1 of any suitable contour, the bed illus trated being circular in contour andhaving :1 depending rim 2 to aflord a space beneath the bed proper within which a shaft 3 may be disposed. This shaft is journaled at its left hand end directly in the rim 2 of the bed and at its right hand end it is journaled in a bearing at that is threaded into the rim of the bed, there being'a set screw 5 in the rim of the bed that is screwed against the bearing d to hold it in place and which screw, when loosened, will permit the withdrawal of the said bearing. Except for small zonesat the mid and end portions of the shaft the shaft is threaded in one direction upon one end and in an opposite direction upon the other end. Two blocks 6 and 7 are in threaded connection with the shaft, the threads therein corresponding in direction tothe threads upon the parts of the shaft respectively passing therethrough. These blocks 6 and 7 extend upwardly into a slot 8 formed diametrically across the bed 1, the shaft 3 extending along and being disposed: beneath said slot; The blocks cross and extend beyond the slot and underlie the bed preferably on both sides of the slot as indicated in Fig. t. These blocks are desirably in constant sliding engagement with the portions of the bed that margin the slot 8 lengthwise so that there is no appreciable upright movement of the blocks with respect to the bed. These blocks are desirably formed. of bronze and carry screws 9 that are made of steel and are therefore made separately from the blocks if the latter are of bronze or other material than steel. Pins 10 are passed through the screws 9 and into the blocks 6 and 7 so that each screw is held in rigid relation to the block carrying it. Clamping jaws 11 are assembled with the blocks, these jaws being movable up and down with respect to the blocks. The screws 9 pass through these jaws and are provided with nuts 12 upon their top ends. These nuts are provided with handles 13 by which they may be turned to force the jaws downwardly toward or upon the bed. The jaws are provided with prongs 14 upon their inner faces. The jaws are preferably normally spaced apart from the bed by means of the upright coiled springs 15, there being two such coiled springs for each jaw and upon opposite sides of the slot. The upper abutment of each spring is desirably in the form of a threaded block 16 having a screw driver slot 17 By turning this plug the compression of the corresponding spring may be adjusted to regulate its jaw lifting effect. The lower abutment of each spring is in the form of another plug 18 which, however, slides within the corresponding space 19 that contains the associate spring 15. l/Vhen the device is idle the springs 15 support the jaws a slight distance above the bed 1 and afford clearance between the jaws and the upper ends of the blocks 6 and 7 to pernnt the jaws to be depressed against the force of the springs when an object such as a printing block 20 is clamped between the jaws. When the object is to be thus clamped the shaft 3 is turned as by means of a detachable crank 21. The prongs 14 slope downwardly upon their top sides and their under faces are horizontal so that as the clamps are moved toward each other as a consequence of the clockwise rotation of the shaft 8, the object 20, while being clamped between the jaws, may also be moved downwardly slightly by said prongs rather than upwardly, the space between the object 20 and the bed being a little less than the space between the jaws and the bed as illustrated in Fig. 3. WVhen this much of the clamping adjustment has been effected the handles 13 are turned clockwise to screw the nuts 12 vertically and downwardly upon the top sides of the jaws and against the face of the spring 15 whereby the object 20 is also depressed and brought into firm engagement with the top face of the bed.

If the mechanism illustrated is a part of a planer the working height to which the object 20 is brought by the planing tool corresponds exactly to the distance between the top face of the bed and the cutting edge of the planing tool.

In assembling the parts, the elements 3, 4 and 5 are out of place, permitting the blocks 6 and 7 to be assembled with the threaded bores that are in alignment with the openings in the rim 2 of the bed that contain the ends of the shaft The screw is passed through the right hand opening (Fig. 2) in the rim of the bed and by suitable manipulation of the screw and the blocks the desired assembly of the screw and blocks is effected. At a suitable stage in the assembly of the parts the bearing sleeve 4- is re red into place and is held there by means of the set screw 5.

ll hile l have herein shown and particularly described the preferred embodiment of my invention I do not wish to be limited to the precise details of construction shown as changes may readily be made without departing from the spirit of my invention, but having thus described my invention I claim as new and desire to secure by Letters Patent the following 1. In a clamping device, the combination with a bed formed with an elongated slot therein; of a shaft journaled upon said bed and beneath said slot along which the shaft extends; two blocks in threaded connection with said shaft, the threads in one block and the portion of the shaft engaging this block being opposite in direction to the threads in the other block and the portion of the shaft engaging this latter block, said blocks crossing and extending beyond said slot and un derlyin the bed; clamping jaws movable by said blocks along the slot, and movable up and down with reference thereto; screw devices upon the blocks and in depressing engagement with the jaws; and springs between the jaws and bed for elevating the aws.

2. In a clamping device, the combination with a bed formed with an elongated slot therein; of a shaft journaled upon said bed and beneath said slot along which the shaft extends; two blocks in threaded connection with said shaft, the threads in one block and the portion of the shaft engaging this block being opposite in direction to the threads in the other block and the portion of the shaft engaging this latter block, said blocks crossing and extending beyond said slot and underlying the bed; clamping jaws movable by said blocks along the slot, and movable up and down with reference thereto; and screw devices upon the blocks and in depress ing engagement with the jaws.

In a clamping device the combination with a bed formed with an elongated slot therein; of a shaft journaled upon said bed and beneath said slot along which the shaft extends: two blocks in threaded connection with said shaft, the threads in one block and the portion the shaft engaging this block being opposite in direction to the threads in the other block and the portion of the shaft engaging this latter block, said blocks cross ing and extending beyond said slot and un derlying the bed; clamping jaws movable by said blocks along the slot, and movable up and down with reference thereto; and de- Vices for pressing the jaws toward the bed.

t. In a clamping device, the combination with a bed formed with an elongated slot therein; of a shaft journaled upon said bed and beneath said slot along which the shaft extends; two blocks inthreaded connection with said shaft, the threads in one block and the portion of the shaft engaging this block being opposite in direction to the threads in HORACE W. HACKER. 

